JP2001289164A - Variable displacement compressor and method for lubricating oil supply to it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure stable lubrication of a variable displacement compressor, by always supplying a drive chamber with lubricating oil separated by an oil separator during the operation of the compressor. SOLUTION: In this variable displacement compressor of constitution, separating lubricating oil from delivery refrigerant gas by an oil separator 18 to supply the lubricating oil to a drive chamber 7 via a delivery pressure introducing passage 23 opened/closed by a capacity control valve 24, the lubricating oil in the oil separator 18 can be supplied to the drive chamber 7 in addition to the above delivery pressure introducing passage 23 by a reducing passage 25 of separate system therefrom. The reducing passage 25 is constituted by a radial clearance of a slide surface of a cylinder block 1 and a drive shaft 8, and the radial clearance communicates with the delivery pressure introducing passage 23 in the upstream of the capacity control valve 24.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable displacement compressor suitable mainly for vehicle air conditioning, and more specifically, supplies oil (hereinafter, referred to as lubricating oil) contained in a discharged refrigerant gas to a drive chamber (crank chamber). Technology related to (return).

[0002]

2. Description of the Related Art A swash plate type vehicle-mounted variable displacement compressor changes (increases or decreases) the discharge capacity by changing (increase or decrease) the pressure in a drive room in which a swash plate is housed. Is controlled by guiding the discharge pressure to the drive chamber via the opening and closing operation of the displacement control valve. On the other hand, the lubricating oil contained in the discharged refrigerant gas is separated from the refrigerant gas by the oil separator, and then supplied to the drive chamber for lubrication. In the conventional variable displacement compressor, a passage for supplying lubricating oil in the oil separator to the drive chamber is provided with a discharge pressure for driving chamber pressure control for introducing a discharge pressure into the drive chamber for controlling the capacity of the compressor. It was used as an introduction passage.

[0003]

However, when the lubricating oil supply passage is used as a discharge pressure introducing passage set for capacity control as described above, the compressor is 100%
(The swash plate is operated at the maximum discharge capacity inclined at the maximum with respect to the drive shaft), the displacement control valve is closed, so that lubricating oil is not supplied to the drive chamber. Therefore, when the operation at the maximum discharge capacity is continued for a long time, the lubricating oil in the drive room may be insufficient.

The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to always supply lubricating oil separated by an oil separator to a driving chamber during operation. The purpose is to ensure stable lubrication.

[0005]

In order to achieve the above object, a variable displacement compressor according to the present invention has a configuration as described in each of the claims. Therefore, according to the first aspect of the present invention, when the variable displacement compressor is operated at the maximum displacement, the lubricating oil in the oil separator is discharged to the discharge pressure introducing passage due to the closing of the displacement control valve. Is not supplied to the driving chamber via the throttle chamber, but is introduced into the driving chamber via a throttle passage which is always in communication. On the other hand, during the variable displacement operation, the displacement control valve is opened, and at this time, the lubricating oil in the oil separator is supplied to the drive chamber via the discharge pressure introduction passage in addition to the above-described throttle passage. That is, according to the present invention, during operation of the compressor, the lubricating oil separated by the oil separator can be supplied to the drive chamber for lubrication regardless of the opening / closing operation of the capacity control valve.

In this case, the throttle passage is constituted by a radial clearance of a sliding surface between the cylinder block and a drive shaft rotatably penetrated through the cylinder block. Is desirable. In this case, the sliding surface can be lubricated at the same time as the lubricating oil in the oil separator is supplied to the drive chamber through the radial clearance.

Further, as described in claim 3, it is desirable that the throttle passage is constituted by a radial clearance of a sliding surface of a cylinder bore and a piston reciprocating in the cylinder bore. When such a configuration is employed, the sliding surface can be lubricated while the lubricating oil in the oil separator is supplied to the drive chamber through the radial clearance.

According to the present invention, when the variable displacement compressor is operated at the maximum discharge capacity,
The displacement control valve is closed, so that the lubricating oil in the oil separator is supplied to the drive chamber via the throttle passage. on the other hand,
During the variable displacement operation, the displacement control valve is opened, and the lubricating oil in the oil separator is supplied to the drive chamber via both the throttle passage and the discharge pressure introduction passage. Therefore, lubricating oil can always be supplied to the drive chamber during operation of the variable displacement compressor.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. 1 is a longitudinal sectional view of a variable displacement compressor in which a piston is not shown, FIG. 2 is a longitudinal sectional view of a cut portion of the variable displacement compressor different from FIG. 1, and FIG. 3 is an enlarged view of a portion A in FIG. . As shown in FIGS. 1 and 2, a front housing 2 is connected to a front end of a cylinder block 1 that forms a part of an outer shell of the compressor, and a suction chamber 3 and a discharge chamber 4 are formed at the rear end. The rear housing 5 is connected via a valve plate 6.

A drive shaft 8 connected to a power source is inserted into a drive chamber 7 formed in the front housing 2, and the drive shaft 8 penetrates through the cylinder block 1 and the front housing 2 and is rotatably supported. Have been. Drive room 7
A swash plate 11 is accommodated therein, and the swash plate 11 is supported by the drive shaft 8 so as to be slidable in the axial direction and tiltable. Further, a rotor 12 is fixed to the drive shaft 8, and the rotor 12 is linked to the swash plate 11 via a hinge mechanism 13,
The swash plate 11 is integrally rotated, and the swash plate 11 can be tilted. The swash plate 11 is pressurized in the axial direction by balance springs 9 and 10 disposed before and after the swash plate 11, and is maintained at a slight inclination angle of, for example, about 5 degrees while the compressor is stopped. Note that one balance spring 9 is received by the rotor 12 and the other balance spring 1
0 is received by the retaining ring 10a.

The cylinder block 1 is provided with a predetermined number of cylinder bores 14 penetrating at predetermined intervals in a circumferential direction, and a piston 15 is slidably fitted in each cylinder bore 14. The rear side of the piston 15 extends toward the drive chamber 7 and is moored to the swash plate 11 via a shoe 16. Accordingly, the rotational movement of the swash plate 11 is converted into a linear reciprocating movement of the piston 15 via the shoe 16 and the piston 15
Reciprocates in the cylinder bore 14. As a result, the refrigerant in the suction chamber 3 flows from the suction port 26 to the suction valve 2.
After being sucked into the cylinder bore 14 through 7, it is discharged from the discharge port 28 to the discharge chamber 4 through the discharge valve 29 while being compressed. 2 shows the piston 15 at the top dead center position (discharge end position), and the lower side shows the piston 15 at the bottom dead center position (suction end position). Note that the suction valve 27, the discharge valve 29, and the valve presser 30 are fixed to the valve plate 6 by a fixture 31.

A thrust trace 3 for urging the rear end of the drive shaft 8 forward is provided in the shaft hole of the cylinder block 1.
2 and a pressure spring 33 are accommodated, and the urging force of the pressure spring 33 is supported by a thrust bearing 34 interposed between the rotor 12 and the front housing 2.

An oil separator 18 is provided between one bore of the cylinder block 1. The oil separator 18 includes an oil separation chamber 19 formed in the cylinder block 1 and a flanged separation cylinder 20 mounted concentrically in the oil separation chamber 19, and the separation cylinder 20 is fixed by a retaining ring 21. I have. The oil separation chamber 19 is communicated with the discharge chamber 4 by a discharge passage 22. The discharge passage 22 opens substantially tangentially into the oil separation chamber 19. Accordingly, the discharged refrigerant gas flowing from the discharge chamber 4 into the oil separation chamber 19 via the discharge passage 22 passes through the cylindrical hole of the separation cylinder 20 while rotating in the annular gap between the separation cylinder 20 and the external passage (condenser). ). During this time, the lubricating oil mixed in the refrigerant gas collides with the peripheral wall of the oil separation chamber 19 due to centrifugal force, is separated from the refrigerant, and flows down to the bottom of the oil separation chamber 19.

The oil separation chamber 19 is connected to the drive chamber 7 by a discharge pressure introduction passage 23 provided in the cylinder block 1. Therefore, the lubricating oil in the oil separation chamber 19 separated from the discharged refrigerant gas is supplied to the drive chamber 7 through the discharge pressure introduction passage 23. The opening and closing of the discharge pressure introducing passage 23 is controlled by a capacity control valve 24 attached to the cylinder block 1. As the capacity control valve 24, for example, an external control type electromagnetic valve having a valve body for opening and closing a passage and a solenoid for opening and closing the valve body is used, and the discharge connected to the drive chamber 7 by excitation / non-excitation of the solenoid. Pressure introduction passage 2
Open and close 3

The discharge capacity of the variable displacement compressor is determined by the piston 1
5 determined by the magnitude of the stroke, the piston 1
The stroke amount of 5 is determined by the inclination angle of the swash plate 11. That is, as the inclination angle of the swash plate 11 increases, the stroke of the piston 15 increases, and the discharge capacity increases. As the inclination angle decreases (approaches a right angle to the drive shaft 8), the stroke of the piston 15 decreases. Thus, the discharge capacity is reduced. The tilt angle of the swash plate 11 during operation is determined by the pressure difference acting on the head surface and the back surface of the piston 15, that is, the pressure difference in the cylinder bore 14 and the pressure in the drive chamber 7, and this pressure difference is determined by the displacement control valve 24. It is adjusted by the opening and closing operation of. The opening / closing operation of the capacity control valve 24 is controlled by control means (not shown). The control means detects, for example, the suction pressure, and opens the capacity control valve 24 when the detected value exceeds a reference value. When it is lower than the reference value, it is operated to close.

When the displacement control valve 24 is operated to the open side, the pressure on the discharge side is discharged through the discharge pressure introduction passage 23 to the drive chamber 7.
And the pressure in the drive chamber 7 is increased. On the other hand,
When the displacement control valve 24 operates to the closing side, the discharge pressure introducing passage 23 is closed, and the supply of the discharge side pressure to the drive chamber 7 is shut off. Since the drive chamber 7 communicates with the suction chamber via a passage (not shown), when the supply of the discharge side pressure is interrupted, the pressure in the drive chamber 7 gradually decreases.

In the variable displacement compressor as described above, the discharge pressure introducing passage 23 has an annular passage 23a on the fitting surface of the cylinder block 1 with the drive shaft 8 in the middle thereof. The annular passage 23a is provided upstream of the displacement control valve 24, and is always driven through a throttle passage 25 (see FIG. 3) formed by a radial clearance of a sliding surface between the cylinder block 1 and the drive shaft 8. It communicates with 7. As described above, the discharge pressure introduction passage 23 is
4 and a throttle passage 25 around the drive shaft 8.
The passage of the system communicates with the drive room 7.

As described above, in the variable displacement compressor according to the present embodiment, the discharge capacity is made variable by changing the pressure in the drive chamber 7, and the pressure in the drive chamber 7 is The discharge pressure in the oil separator 18 is controlled by being guided to the drive chamber 7 through the discharge pressure introduction passage 23 opened and closed by the capacity control valve 24. Accordingly, when the variable displacement compressor is operating at the maximum discharge capacity, the displacement control valve 24 is closed, so that the lubricating oil in the oil separator 18 is supplied to the drive chamber 7 via the discharge pressure introduction passage 23. Never. However, since the annular passage 23 a of the discharge pressure introducing passage 23 is always communicated with the drive chamber 7 via the throttle passage 25, the lubricating oil in the oil separator 18 is supplied to the drive chamber 7 via the throttle passage 25. Will be. On the other hand, during variable displacement operation of the variable displacement compressor,
Since the capacity control valve 24 is opened, the oil separator 1
8, the lubricating oil flows through the discharge pressure introducing passage 23,
The air is supplied to the drive chamber 7 through two paths, namely, the flow through the throttle passage 25.

As described above, according to the present embodiment, during operation of the compressor, the lubricating oil separated from the refrigerant gas discharged by the oil separator 18 is constantly driven regardless of the opening / closing operation of the capacity control valve 24. 7 can be supplied. For this reason, even if the operation at the maximum discharge capacity with the capacity control valve 24 closed is continuous for a long time, there is no fear that the lubricating oil in the drive chamber 7 runs short. As a result, the swash plate 11, the shoe 16, and the piston 1
The lubrication effect of each sliding portion such as the sliding surface of No. 5, the sliding surface of the hinge mechanism 13, which is the link between the rotor 12 and the swash plate 11, and the sliding surface of the drive shaft 8 and the swash plate 11 can be secured. .

In this embodiment, the cylinder block 1
Since the radial clearance of the sliding surface between the motor and the drive shaft 8 is used as the throttle passage 25, not only the function of supplying lubricating oil to the drive chamber 7 but also the effect of lubricating the sliding surface can be obtained. Further, it is not necessary to perform a drilling process for setting the throttle passage 25 in the cylinder block 1.

FIG. 4 shows another embodiment of the present invention. In this embodiment, the throttle passage 25 that connects the oil separator 18 and the drive chamber 7 is constituted by the side clearance of the sliding surface between the piston 15 and the cylinder bore 14. An annular passage 23 a is formed on the inner peripheral surface of the cylinder bore 14, and the annular passage 23
The throttle passage 25 communicates with the discharge pressure introduction passage 23 in the above-described embodiment by a. Specifically, the discharge pressure introduction passage 23 from the oil separator 18
Is guided around one or more cylinder bores 14 to form an annular passage 23a on the inner peripheral surface of the cylinder bore.
Therefore, in the present embodiment, the lubricating oil separated from the refrigerant gas discharged by the oil separator 18 during the operation of the compressor is always irrespective of the opening / closing operation of the capacity control valve 24, similarly to the above-described embodiment. It can be supplied to the drive chamber 7 for lubrication, and the sliding surface between the piston 15 and the cylinder bore 14 can be lubricated.

The throttle passage 25 is not limited to the side clearance described above, but may be formed in the cylinder block 1 by, for example, drilling.

[0023]

As described in detail above, according to the present invention,
During operation of the variable displacement compressor, the lubricating oil in the oil separator can always be supplied to the drive chamber for lubrication. For this reason, the problem of lack of lubricating oil in the drive room can be avoided, and the lubrication of the sliding portion can be improved.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a variable displacement compressor.

FIG. 2 is a longitudinal sectional view of a cut portion of the variable displacement compressor different from FIG. 1;

FIG. 3 is an enlarged view of a portion A in FIG. 1;

FIG. 4 is an explanatory diagram showing another embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Cylinder block 3 ... Suction chamber 4 ... Discharge chamber 7 ... Drive chamber 8 ... Drive shaft 11 ... Swash plate 12 ... Rotor 14 ... Cylinder bore 15 ... Piston 18 ... Oil separator 23 ... Discharge pressure introduction passage 24 ... Capacity control valve 25 ... Throttle passage

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Taku Yasutani 2-1-1 Toyota-cho, Kariya-shi, Aichi Pref. Inside Toyota Industries Corporation (72) Inventor Ryo Matsubara 2-1-1 Toyota-cho, Kariya-shi, Aichi Pref. Inside the Toyota Industries Corporation (72) Inventor Hirotaka Kurakake 2-1-1 Toyota-cho, Kariya-shi, Aichi Prefecture Inside the Toyota Industries Corporation (72) Inventor Hiroyuki Yoshida 2-1-1 Toyota-cho, Kariya-shi, Aichi Prefecture Shares F term in Toyota Industries Corporation (reference) 3H003 AA03 AB07 AC03 BD03 BD08 BD12 BG09 BH06 CA02 CC09 CC11 CE01 3H076 AA06 BB16 BB17 BB26 BB28 BB40 BB41 BB43 CC12 CC20 CC28 CC33 CC36 CC46 CC62 CC69 CC70 CC85 CC99

Claims (4)

[Claims] 1. A piston which reciprocates in a cylinder bore, compresses refrigerant gas sucked from a suction chamber and discharges it to a discharge chamber, and a tilt displacement which rotates together with a drive shaft in a drive chamber and changes the stroke of the piston. A possible swash plate, an oil separator for separating the lubricating oil contained in the discharged refrigerant gas, a discharge pressure introducing passage for introducing the lubricating oil in the oil separator into the drive chamber, and provided in the discharge pressure introducing passage, A variable displacement compressor comprising: a displacement control valve that changes the pressure in the drive chamber by opening and closing to change the displacement, and a throttle passage that communicates the oil separator with the drive chamber. 2. The variable displacement compressor according to claim 1, wherein the throttle passage is formed by a radial clearance of a sliding surface between the cylinder block and a drive shaft rotatably penetrating the cylinder block. A variable displacement compressor characterized by being constituted. 3. The variable displacement compressor according to claim 1, wherein the throttle passage is formed by a radial clearance of a sliding surface between the cylinder bore and a piston reciprocating in the cylinder bore. A variable capacity compressor characterized by the following. 4. A piston which reciprocates in a cylinder bore, compresses refrigerant gas sucked from a suction chamber and discharges it to a discharge chamber, and a tilt displacement which rotates together with a drive shaft in a drive chamber and changes the stroke of the piston. A possible swash plate, an oil separator for separating the lubricating oil contained in the discharged refrigerant gas, a discharge pressure introducing passage for introducing the lubricating oil in the oil separator into the drive chamber, and provided in the discharge pressure introducing passage, A lubricating oil supply method for a variable displacement compressor including a displacement control valve that changes a discharge capacity by changing the pressure in the drive chamber by opening and closing operation, and a throttle passage communicating the oil separator and the drive chamber. At the time of the maximum discharge operation, the displacement control valve is closed, and the lubricating oil separated by the oil separator is supplied to the drive chamber through the throttle passage, and is changed. During the volume operation, the displacement control valve is opened to supply the lubricating oil separated by the oil separator to the drive chamber through both the throttle passage and the discharge pressure introduction passage. Oil supply method.